1. Field of the Invention
The present invention relates generally to composite materials, and more specifically, to a system and method for integral fiber hinges in composite materials.
2. Discussion of the Related Art
This invention relates to creating an integral hinge in a composite material. Throughout the text, “composite material” means materials made from two or more constituent materials with different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure. Composite materials are made up of individual materials referred to as constituent materials. There are two main categories of constituent materials: matrix and reinforcement. At least one portion of each type is required. The matrix material surrounds and supports the reinforcement materials by maintaining their relative positions.
Integral non-articulated hinges, for example of the so-called film-hinge type, have been known for a long time, and form the basis of many applications, in particular, in the field of packaging. In general, they consist of a local reduction in thickness of materials resilient in flexure, thus making it possible to form a more flexible portion between two stiffer portions of such materials. The flexibility due to the reduction of thickness is typically permanent.
Integral non-articulated hinges can also be formed by integrating a separate, more flexible material into the composite during its manufacture. This typically requires multiple materials and consideration of the bond between the composite and hinge materials. As with the film hinge, the flexibility of the hinge is a typically a permanent part of the finished material.
Another practice is to use a separate hinge, for example metal, that joins two separate pieces of composite material. The hinge typically must be made separately from the composite parts and often must be joined to the composite parts by drilling, fastening, bonding or other means.
Composite shapes are typically formed in an open or closed forming mold. The use of a mold limits the forming of composite shapes. For example, a closed sphere cannot be molded without including the inner form in the final product.
Accordingly, what is needed is a hinge that overcomes the disadvantages of the aforementioned hinges.